1. Technical Field
The present invention relates to a projection system.
2. Related Art
There is a known projector of related art that projects an image on a screen (see JP-A-2004-94175, for example).
The projector described in JP-A-2004-94175 includes an optical unit formed of a liquid crystal panel as a light modulator that modulates a light flux having exited out of a light source apparatus to form an optical image corresponding to image information and a projection lens that projects the optical image. The projector is further provided with an optical filter in a position downstream of the projection lens, and the optical filter reflects part of green light to improve sharpness of the projected image.
Some projectors are capable of adjusting the position where an image is projected and the factor at which the image is enlarged/reduced by moving a projection lens itself in a direction perpendicular to the optical axis of the projection lens and moving a zoom lens in the projection lens along the optical axis.
When a projector of this type is provided with the optical filter described in JP-A-2004-94175 as a member separate from the projection lens, the movement of the projection lens displaces the positions of the projection lens and the optical filter from each other, causing a problem of inappropriate light incidence on the optical filter.